Systems which utilize spread spectrum communication techniques, such as Direct-Sequence-Code-Division-Multiple-Access (DS-CDMA), have received increased attention over the last decade as a result of the advantages they provide in enhancing multiple access capacity in mobile communication systems. In that light, it is noted that an essential component in spread spectrum communications systems is a Psuedo-Random or Psuedo-Noise (PN) Sequence Generator System. Psuedo-Noise (PN) sequences generated thereby are used at Transmitters to generate wideband signals, and at Receivers to recover narrowband messages. The performance of (DS-CDMA) systems relies on the quality of the signal isolation between the many message signals which share the same frequency band. In that light it is noted that the presence of many interfering users, good isolation can be established by assigning different users different (PN) sequences, which (PN) sequences have nearly orthogonal properties with respect to one another. This, of course, requires the availability of a large space of (PN) sequences with low cross-correlation properties. Conventional (PN) sequences are typified by the class of maximal length (m-) sequences generated by Linear Feedback Shift Registers (LFSR's). However, the number of such sequences generated by LFSR's may be insufficient for wideband (DS-CDMA) systems with a very large number of users. In addition, (LSFR) techniques provide limited flexibility in incorporating security into multiple user systems.
The use of chaotic sequences as spreading waveforms in DS-CDMA communication systems has been recently proposed in articles such as:                “A Chaotic Direct-Sequence Spread Spectrum Communications System”, Heidari-Betani et al., IEEE Trans. on Commun, Vol. 42, pp. 1524, (1994);        “Chaotic Complex Spreading Sequences For Asynchronous DS-CDMA, Part II: Some Theoretical Performance Bounds”, Rovatti et al., IEEE Trans. Circ. Sys., Part I, Vol. 45, No. 4, pp. 496, (1998);        “Non-Average Performance Of Chaos-Based DS-CDMA: Driving Optimization Towards Exploitable Maps”, Mazzini et al., IEEE International Symp. on Circuits and Systems, Geneva, Vol. 1, pp. 723, (2000).        
The inherent capability of generating a large space of (PN) sequences due to sensitivity dependence on initial conditions has been the main reason for exploiting chaos in spread spectrum communication systems. Certain one-dimensional chaotic maps exhibit this property and have been mathematically shown to provide a rich set of sequences when their output is recursively fed back into the map. This is discussed in:                “Chaos: An Introduction To Dynamical Systems”, Alligood et al., Springer, N.Y. (1997); and        “Chaotic Electronics in Telecommunications”, CRC Press, Boca Raton, Fla., (2000).        
Sequences generated in this way diverge to different trajectories in a few itterations even though their initial conditions differ by less than one percent. This behavior demonstrates that it is straight forward to generate a large space of (PN) sequences with nice statistical properties by quantizing the output of an itterative chaotic map. However, reliable electronic hardware implementations of chaos-based (PN) sequence generators based on recursion maps realized by piece-wise linear analog functions and output quantization have not been possible because of manufacturing problems, such as process variations among different integrated circuit production lots, transistor mismatches, and electronic noise. The problem of repeatable and consistent (PN) sequence generation has recently been addressed in the literature and an approach has been presented based on suppressing the potential process and mismatch errors by coarsely quantizing the inputs and outputs of maps. This is discussed in:                “Chaotic Generation of (PN) Sequences”, Dornbusch et al., IEEE Intl. Symp. on Circuits and Systems, Orlando, Vol. V, pp. 454, (1999).        
The problem which develops under this approach is that only a relatively small number of input/output bits for a single map stage are possible because of the coarseness of the quantization. A large number of cascaded map stages are thus required to generate long sequences and a rich sequence space. This leads to increased system complexity.
Additional known relevant references are:                “Fully Programmable, Scalable Chaos Based (PN) Sequence Generation”, IEE Electronics Letters, Vol. 36, No. 16, pp. 1371, (2000); and        “CDMA Engineering Handbook”, Miller et al., Artech House, Norwood, Mass. (1998).        
A Search of Patents has identified some which are generally relevant, none of which, however, are thought to be particularly on-point. Said Patents are:                U.S. Pat No. 5,519,736 to Ishida;        U.S. Pat. No. 5,910,907 to Chen et al.;        U.S. Pat. No. 5,566,099 to Shimada;        U.S. Pat. No. 5,068,872 to Schroter;        U.S. Pat. No. 5,291,555 to Cuomo et al.;        U.S. Pat. No. 5,796,776 to Lomp et al.;        U.S. Pat. No. 4,852,023 to Lee et al.;        U.S. Pat. No. 6,031,865 to Kelton et al.;        U.S. Pat. No. 5,943,361 to Gilhousen et al.;        U.S. Pat. No. 6,148,053 to Ozluturk.        
In particular, no identifed prior art suggests application of directly quantized maps.
Need remains for improved systems and method for generating robust (PN) sequences and rich (PN) sequence space.